Evaluation of some insecticides on brown plant hopper Nilaparvata lugens (Stal.) and its predators in rice.

摘要

A field experiment was undertaken for two cropping seasons during kharif of 2007 and 2008 to evaluate the toxicity of some insecticides against rice brown plant hopper (BPH) and its predators in rice (variety Swarna). The insecticide treatments included buprofezin 25 SC, imidacloprid 17.8 EC, spinoteram 12 SC, thiamethoxam 20 WG, acetamiprid 20 SP, acephate 75 SP and at 200; 45; 100; 40; 40 and 400 g a.i./ha, respectively along with an untreated control. It was revealed that buprofezin followed by imidacloprid; thiamethoxam and acetamiprid were much effective in suppressing the BPH population in rice. BPH/MB ratio was lowest in buprofezin which is favorable for the predators in both the seasons. Spider population was not significantly different from each other. However in kharif of 2008 spider population was higher in spinoteram and buprofezin treated plots with control ranging from 2.3 to 3.3 than the rest of the treatments after 20 DAS.